Worth seafoaming a Yammy 3000 iSE before replacing carb?

My Onan 5500 Gold developed a bad knock. I feared the worst, took it to Giant Recreation World in Ormond Beach.

Tech listened to it and told me to go into the parts dept and buy a can of Onan 4C (cleaner).

I took it home and followed the directions; spraying slowly not letting it stall for a few minutes, then spraying heavy enough to stall.

Let it set a few hours, was like new afterwards.

They build up carbon from oil blow by being air cooled, the rings are looser than a water cooled engine.